To much mid speed damping SHIVER 45

[Klausen]

Today I can test my new stack in race conditions.
(but the rebound is still to soft)

over trunks it feels good - the high speed damping is OK
In sandcorners the front don't buckle - low speed is OK
But over short and many little brake and acceleration bumbs it feels toooooo hard and stiff
I think the mid speed damping is to stiff
How can I solve this problem?

here are the specs

Rebound

spring
15x0,2
15x0,3
15x0,3
22x0,3
11x0,2
piston
21 x 0,1
21 x 0,1
19 x 0,1
19 x 0,1
18 x 0,1
17 x 0,1
15 x 0,1

Base

22x0,3
Piston
22 x 0,1
22 x 0,1
22 x 0,1
11 x 0,2 may be a thicker crossover?
19 x 0,1 1.affect these 2 shims the midvalve or is this a more complex problem
17 x 0,1 2.
11 x 0,1 may be a thicker crossover?
15 x 0,15
14 x 0,15
13 x 0,20
12 x 0,20
11 x 0,20


135mm air
3mm preload
4,5N/mm spring
SAE 5W/10W MIX 1:1 Motul Expert

[twowheels]

Originally Posted by Klausen

Base

22x0,3
Piston
22 x 0,1
22 x 0,1
22 x 0,1
11 x 0,2 may be a thicker crossover?
19 x 0,1 1.affect these 2 shims the midvalve or is this a more complex problem
17 x 0,1 2.
11 x 0,1 may be a thicker crossover?
15 x 0,15
14 x 0,15
13 x 0,20
12 x 0,20
11 x 0,20

Klausen: I understand you 99% of the time, but could you try again for your compression stack questions. I think you're referring to the mid-speed damping as your mid-valve ... is that correct?
As far as thicker crossovers go, you will delay the onset of the next damping stage, but the stiffness will be unchanged.

[Klausen]

you will delay the onset of the next damping stage

What is the sense of this, what means more or less delay on the track?

Klausen: I understand you 99% of the time, but could you try again for your compression stack questions. I think you're referring to the mid-speed damping as your mid-valve ... is that correct?
As far as thicker crossovers go, you will delay the onset of the next damping stage, but the stiffness will be unchanged.

No my problem refers really to the mid-speed damping.

Region II: Mid Speed

Mid-speed damping is controlled by the combined force of the base and mid-valve. MX suspension setups use stiff mid-valve shim stacks to control bottoming on large hits. Enduro setups use softer mid-valve shim stacks and larger values of stack float to allow the suspension to absorb bumps rather then jump over them.
Source shimrestackor

I think the mentioned track conditions are mid speed.

Over short and many little brake and acceleration bumbs it feels to hard or harsh the front feels unstable and jumps to much over the bumps.

I read that less rebound solve this probs but my rebound is to soft.
Also I read that the Shiver 45 have an issue where too little rebound feels like too much compression. My be is this the problem.

When I jump a table to short and land on the top the same.

When ride very fast a rutty dirt road the handle bar is weaving
(I read this can cause to stiff springs but I think the 4,5 N/mm are OK for me with 85kg without wear)

[GMP]

Also I read that the Shiver 45 have an issue where too little rebound feels like too much compression. My be is this the problem

Absolutely!

This fork needs a lot more rebound. I rode yesterday with even more rebound than my previous setup, it was fantastic, as was the shock that LTR serviced and tweaked. The fork stays down in the corners a lot better, is controlled, and does not pack. I'm riding rocks and if packing was a problem I would experience it. This fork was always good but now its just awesome.

Have you noticed your rebound clickers have little effect? Thats from the free bleed in the piston and bleed shim setup. Get rid of most of this and things will get a lot better.

[Klausen]

Have you noticed your rebound clickers have little effect?

with this Setup I feel almost nothing when I turn the rebound screw
actual stack Marzocchi 2006

21 x 0,1
21 x 0,1
19 x 0,1
19 x 0,1
18 x 0,1
17 x 0,1
15 x 0,1

I use Motul expert Oil 5W /10W mixed 1:1 (26,9 reported cst@40C° [centistokes])
(for your info genuine Marzocchi original 7,5 W (26,10 reported cst@40C° [centistokes]))
air 135mm
preload 3mm
4,5 N/mm springs

today I change the rebound stack again.
the biggest change was the bleed shim from 21x0,1 to 22x0,1

22 x 0,1
21 x 0,1
19 x 0,1
19 x 0,1
17 x 0,1
17 x 0,1
15 x 0,1

Motul expert Oil 5W /10W mixed 1:1
air 125mm
preload 5mm
4,5 N/mm springs

Now I feel something when I turn the screw.

The feeling on the track was really better.
But I don't know exactly why ,because I change also the Basevalve and the Midvalve.

Thats from the free bleed in the piston and bleed shim setup. Get rid of most of this and things will get a lot better.

What do you mean exactly?
How are your stacks changed?

[GMP]

Well you have fixed the worst part by going to a 22mm face shim. There is a bleed hole in the piston as well but I left that alone. My stack is similar, but I added a 13mm clamp to stiffen the whole thing and I like it a lot. I'm running .44kg/mm springs with very little preload (1 - 2 mm), B rider in rocky terrain.

22x.01
22x.01
19x.01
19x.01
18x.01
17x.01
15x.01
13x.01

[Klausen]

There is a bleed hole in the piston as well but I left that alone.

What can I do with the bleed hole?

I think very importend is also the oil viscosity.
Which brand and weight you use.

Do you also change te Mid valve and Base Stack?
How?

[moto9]

My understanding of the mid-valve's function is it acts more like a drag chute...to slow the fork's speed at higher velocities.
That would come more into play on bigger hits, like jumps and G-outs.
However, it does somewhat come into play on small rough stuff, but only slightly.
That's why in most cases the float is not set more than 1mm to 1.5mm, other wise the fork would blow thru the stroke too quickly, unless that's compensated for at the BV...as done in the Race Tech kits.

Then there's the Smart Taco kit that uses a adjustable preloaded mid-valve set up...that adds a whole other adjustment to the fork's action.

I set the float at 1mm but I used a .010 thickness face shim for a little added H/S shim deflection.
I want the MV to open quickly and also be able to handle the larger square root and rock ledges, but I don't want the fork to blow too far into the stroke.

If I wanted the fork more compliant in the small rough sections I would soften the high speed portion of the BV

I am also working on tightening up the H/S rebound.

[GMP]

Leave the bleed hole and adjust the stack. At higher piston speeds the hole is out of the equation anyway, and its the initial quick return after a deep compression that feels like a compression issue. I run Spectro 125/150 which is around 7 -7.5W but to be accurate you need to compare viscosity index not advertised weights.

The stock MV is just a high float check plate setup with 3 .3mm plates. For an MV setup you should use a .15 face shim, as the .10s get hammered fast. If your playing with midvalves remember that the amount of available deflection is important to eliminate harshness, as all the oil in the cartridge that does not flow through the base valve (amount displaced by the damper rod) must flow through the midvalve. Also, the more deflection the more intensive the maintanence, as in moto9s setup. WPs are particularly bad, I have seen a friends loose all rebound control during a ride, and later found totally destroyed MV face shims the cause.

My base valve stack is setup for rocks with light HS compression. LTR does my stuff so I will not post any specifics. I just play with the rebound and MV some to learn.

[Klausen]

Leave the bleed hole and adjust the stack.

I leave it alone.
I only want to know what I can change with that hole. And how.

I run Spectro 125/150 which is around 7 -7.5W but to be accurate you need to compare viscosity index not advertised weights.

I use Motul expert Oil 5W /10W mixed 1:1 (26,9 reported cst@40C° [centistokes])
genuine Marzocchi original 7,5 W (26,10 reported cst@40C° [centistokes])
I don't find yours in the table.
http://www.gasgasrider.org/forum/sho...?t=7087&page=2
IMHO I think when we discuss about stacks the oil viscosity is very importend.

Thanks for you explanation.
Later I will understand it may be.